The present invention relates to a liquid crystal display apparatus having a new configuration.
Conventional liquid crystal display apparatuses employ a display mode represented by a Twisted Nematic (TN) display mode and in which electric fields are applied substantially perpendicularly to a substrate surface (these electric fields are herein after referred to as “vertical fields”). The TN display mode, however, has the disadvantage of using a small angle of visibility.
On the other hand, an In-Plane Switching (IPS) display mode has been proposed in JP-B-63-21907, U.S. Pat. No. 4,345,249, WO No. 91/10,936, and JP-A-6-160878 and etc. specifications.
In this IPS display mode, an electrode for driving liquid crystals is formed on one of a pair of substrates that sandwiches the liquid crystals there between, and electric fields substantially parallel with a surface of the substrate (these electric fields are hereinafter referred to as “horizontal fields”) are applied to the liquid crystals. This display mode provides a larger angle of visibility than the TN display mode.
FIG. 2 is a schematic sectional view showing an example of a configuration of a pixel portion of a liquid crystal display apparatus using the IPS display mode. The liquid crystal display apparatus has a substrate 1, a substrate 2 arranged opposite the substrate 1, a liquid crystal layer 12 sandwiched between the substrates 1 and 2, common electrodes 3 and pixel electrodes 4 for applying horizontal fields, insulated films 6a and 6b disposed on the substrate 1, a liquid-crystal orientation control layer 7 (herein after referred to as an “orientation film”) disposed on the insulated film 6b, a color filter 8 and an orientation film 7 disposed on the substrate 2, and polarizing plates 11 disposed on surfaces of the substrates 1 and 2 which do not face the liquid crystals, the polarizing plates having their own optical characteristics varied according to an orientation state of the liquid crystals. The common electrodes 3 and 4 are linear and are arranged substantially in parallel.
In the IPS display mode, the common electrodes 3 and the pixel electrodes 4 generate horizontal fields as shown by equipotential lines in FIG. 2. Images are displayed when these fields cause the liquid crystals to rotate within a plane substantially parallel with the substrate 1.